Here’s why you should be proud of ISRO’s most powerful rocket, the GSLV Mk III

Meet the newest toy in ISRO's already impressive arsenal

ISRO has just launched its biggest and heaviest rocket ever – the GSLV Mk III – and to put it simply, it’s a big deal (quite literally). Sure, ‘104 satellites in one go’ sounds great for PR pitch. But not taking anything away from ISRO’s previous achievements, the rocket that took off from ISRO’s island base off the coast of Andhra Pradesh a few hours ago is one that truly marks an inflection point in the organisation’s history – a history that’ll hit 50 years in 2019.

To explain the importance of it in as ELI5 a manner as possible – the GSLV Mk III is the rocket ISRO is hoping will one day take our future astronauts into space. And even though ISRO is currently employing the GSLV Mk III for somewhat menial chores (like launching comm satellites), its significance really lies beneath the surface. The GSLV Mk III, while important as a rocket, is more significant for housing India’s first indigenous cryogenic engine – a feat that has taken ISRO 30 years of its 48-year history. According to ISRO, the cryogenic engine has been developed completely from scratch – which means ISRO has the complete intellectual ownership for using the technology. It is a technology seen as being crucial for launching heavier payloads – which in this case is the GSAT-19 at 3,136 kg. However, at max-capacity, the Mk III can carry upto four tonnes – significantly higher than ISRO’s current vehicle of choice and its work-horse, the PSLV (which maxes out at 1,750 kg for low earth orbits).

The difference really is in the fuel and the engine – much like cars on the ground – the more it can carry, the longer the range and heavier the lift capacity. While the PSLV uses solid and liquid fuel alternatively in four stages, the GSLV – thanks to the fuel being stored cryogenically (meaning at extremely low-temperatures) can carry a lot more fuel and therefore has that much more punch power.

GSLV Mk III’s Cryogenic upper stage

The current capacity of the GSLV Mk III is much lower than that of the world’s biggest rockets such as the Space X’s recently-launched Falcon Heavy, which can carry a whopping 58 Metric Tonnes in payload (more than most commercial airliners). But given the stellar rise of ISRO in recent years getting to even keel with the likes of NASA and Space X is only a matter of time.

As for the technology itself, if you’ve ever wondered why despite such feats as sending probes to Mars has India not been able to send people into space (something the US and USSR did in the early ’60s) – this was it. While we can rejoice that the time when an Indian aboard an Indian-made rocket takes off into space from Indian soil is not far away – now would be a good time to start dreaming about becoming an astronaut from India without having to worry about getting an American Green Card first (which might now be tougher than the former).